The objective of this research is to gain an understanding of the mechanism and regulation of oxidative reactions in microorganism. It is proposed to study the electron transport pathways of Pseudomonas putida which has an inducible mono-oxygenase, cytochrome P-450, as well as normal electron tranport for oxidative phosphorylation. This organism was chosen because the cytochrome P-450 is soluble and quite easy to purify. This cytochrome P-450 is being used as a model for mammalian membrane bound cytochrome P-450 to elucidate the mechanism of substrate binding and hydroxylation. The specific goals for the year are:: 1) Studies of the interaction of putidaredoxin with cytochrome P-450 utilizing the freeze quenching apparatus to identify reaction intermediates. 2) Delineation of the nature of the control of cytochrome P-450 catalyzed reactions both in vitro and in vivo. 3. Determination of the components of the normal membrane bound electron transport system of P. putida. 4) Determination of the ligands of ferrous cytochrome P-450 and how they participate in the hydroxylation reaction.